Our current emphasis is on radical alkylation carcinogenesis by carbon tetrachloride and the like. Our questions are: a) what reactions occur between base residues and radical species such as .CCl3 and .CH3, b) how are the radicals bound to DNA, and c) what are the subsequent physicochemical changes. Our approach is to conduct reactions of .CX3 with nucleosides A, C, G, T, U, and follow rates. This will be followed by a similar study with DNA.